Regional distribution of measurement error in diffusion tensor imaging

Marenco, Stefano; Rawlings, Robert; Rohde, Gustavo K.; Barnett, Alan S.; Honea, Robyn A.; Pierpaoli, Carlo; Weinberger, Daniel R.

doi:10.1016/j.pscychresns.2006.01.008

« Previous Next »Psychiatry Research: Neuroimaging
Volume 147, Issue 1 , Pages 69-78, 30 June 2006

Regional distribution of measurement error in diffusion tensor imaging

Stefano Marenco
- Genes, Cognition and Psychosis Program, Clinical Brain Disorders Branch, IRP, NIMH, Bethesda, MD 20892, United States
- Corresponding author. NIMH, CBDB, 10 Center Drive, Building 10, room 4S235, Bethesda, MD 20892, United States. Tel.: +1 301 435 8964; fax: +1 301 480 7795.
Robert Rawlings
- Section for Brain Electrophysiology and Imaging, LCS, IRP, NIAAA, Bethesda, MD, United States
Gustavo K. Rohde
- Section of Tissue Biophysics and Biomimetics, LIMB, IRP, NICHD, Bethesda, MD, United States
- Currently at the Naval Research Laboratory, Washington, DC 20375.
Alan S. Barnett
- Genes, Cognition and Psychosis Program, Clinical Brain Disorders Branch, IRP, NIMH, Bethesda, MD 20892, United States
Robyn A. Honea
- Genes, Cognition and Psychosis Program, Clinical Brain Disorders Branch, IRP, NIMH, Bethesda, MD 20892, United States
Carlo Pierpaoli
- Section of Tissue Biophysics and Biomimetics, LIMB, IRP, NICHD, Bethesda, MD, United States
Daniel R. Weinberger
- Genes, Cognition and Psychosis Program, Clinical Brain Disorders Branch, IRP, NIMH, Bethesda, MD 20892, United States

Received 31 May 2005; received in revised form 28 November 2005; accepted 2 January 2006.

Abstract

The characterization of measurement error is critical in assessing the significance of diffusion tensor imaging (DTI) findings in longitudinal and cohort studies of psychiatric disorders. We studied 20 healthy volunteers, each one scanned twice (average interval between scans of 51±46.8 days) with a single shot echo planar DTI technique. Intersession variability for fractional anisotropy (FA) and Trace (D) was represented as absolute variation (standard deviation within subjects: SDw), percent coefficient of variation (CV) and intra-class correlation coefficient (ICC). The values from the two sessions were compared for statistical significance with repeated measures analysis of variance or a non-parametric equivalent of a paired t-test. The results showed good reproducibility for both FA and Trace (CVs below 10% and ICCs at or above 0.70 in most regions of interest) and evidence of systematic global changes in Trace between scans. The regional distribution of reproducibility described here has implications for the interpretation of regional findings and for rigorous pre-processing. The regional distribution of reproducibility measures was different for SDw, CV and ICC. Each one of these measures reveals complementary information that needs to be taken into consideration when performing statistical operations on groups of DT images.